Merge pull request #1317 from iglesias/feature/fix_matrixlist

Fix discrete libshogun HM-SVM example

examples/undocumented/libshogun/structure_discrete_hmsvm_bmrm.cpp

@@ -10,13 +10,14 @@ int main()
 {
 	init_shogun_with_defaults();
 
-	float64_t features_dat[] = {0,1, 2,1, 0,1, 0,2};
-	SGMatrix<float64_t> features_mat(features_dat,1,8,false);
-	CMatrixFeatures<float64_t>* features = new CMatrixFeatures<float64_t>(features_mat,2,4);
+	float64_t features_dat[] = {0,1,1, 2,1,2, 0,1,0, 0,2,2};
+	SGMatrix<float64_t> features_mat(features_dat,1,12,false);
+	CMatrixFeatures<float64_t>* features = new CMatrixFeatures<float64_t>(features_mat,3,4);
 
-	int32_t labels_dat[] = {0,0, 1,1, 0,0, 1,1};
-	SGVector<int32_t> labels_vec(labels_dat,8,false);
-	CSequenceLabels* labels = new CSequenceLabels(labels_vec,2,4,2);
+	int32_t labels_dat[] = {0,0,0, 1,1,1, 0,0,0, 1,1,1};
+	SGVector<int32_t> labels_vec(labels_dat,12,false);
+	CSequenceLabels* labels = new CSequenceLabels(labels_vec,3,4,2);
+	labels->io->set_loglevel(MSG_DEBUG);
 
 	CHMSVMModel* model = new CHMSVMModel(features, labels, SMT_TWO_STATE, 3);
 	CDualLibQPBMSOSVM* sosvm = new CDualLibQPBMSOSVM(model, labels, 5000,0);

src/shogun/structure/HMSVMModel.cpp

@@ -320,6 +320,10 @@ CResultSet* CHMSVMModel::argmax(
 		}
 	}
 
+	REQUIRE(opt_path[T-1]!=-1, "Viterbi decoding found no possible sequence states.\n"
+			"Maybe the state model used cannot produce such sequence.\n"
+			"If using the TwoStateModel, please use sequences of length greater than two.\n");
+
 	for ( int32_t i = T-1 ; i > 0 ; --i )
 		opt_path[i-1] = trb[opt_path[i]*T + i];